1.在Xencenter里光驱换成xs-tools.iso

2.登陆SSH：
[root@ns0 ~]# cd /mnt

[root@ns0 mnt]# ls

[root@ns0 mnt]# mkdir xs-tools

[root@ns0 mnt]# mount /dev/xvdd /mnt/xs-tools/

mount: block device /dev/xvdd is write-protected, mounting read-only

[root@ns0 mnt]# cd /mnt/xs-tools/Linux/

[root@ns0 Linux]# bash install.sh

Detected `CentOS release 5.2 (Final)' (centos version 5).

The following changes will be made to this Virtual Machine:
* packages to be installed/upgraded:
- kernel-xen-2.6.18-53.1.13.el5.xs4.1.0.24.x86_64.rpm
- xe-guest-utilities-4.1.0-257.x86_64.rpm

Continue? [y/n] y

Preparing...########################################### [100%]
1:xe-guest-utilities########################################### [100%]
Preparing...########################################### [100%]
package kernel-xen-2.6.18-92.el5 (which is newer than kernel-xen-2.6.18-53.1.13.el5.xs4.1.0.24) is already installed

You should now reboot this Virtual Machine.
重启完成安装。